Liquid crystal display devices are such flat panel display devices that become increasingly popular at present, and for example, Thin Film Transistor-Liquid Crystal display is one of them. A liquid crystal panel is one of main components in a liquid crystal display device. The liquid crystal panel is formed by cell-assembling of a color filter substrate and an array substrate, between which, there is formed a liquid crystal cell within which a liquid crystal material is filled. As shown in FIG. 1, an effective display area 4 and a peripheral area 5 are included in the liquid crystal panel. Generally, in the color filter substrate, there are included a first base substrate 1 and multilayer structures, namely, a black matrix 12, a color filter layer 13, a flat protective layer 14 and so on that are provided on the first base substrate 1; and in the array substrate, there are included a second base substrate 2 and multilayer structures, namely, a TFT switch element and an electrode line and a scan line that correspond to it, an insulating layer 22 and so on that are provided on the second base substrate. In order to allow liquid crystal molecules to arrange in a specific direction when they are driven by an external voltage, liquid crystal aligning layers are usually provided on inner sides of the color filter substrate and the array substrate, respectively. Namely, a first liquid crystal aligning layer 15 is provided on the protective layer 14 of the color filter substrate, and a second liquid crystal aligning layer 23 is provided on the insulating layer 22 of the array substrate. Furthermore, in a gap between edges of the color filter substrate and the array substrate, in order that the liquid crystal material is fixed and sealed in the liquid crystal panel, it is also necessary that a sealant 3 be coated in the peripheral area 5 of the liquid crystal panel and solidified. An initial arrangement state of liquid crystal molecules is controlled by the aligning layers of the array substrate and the color filter substrate of the liquid crystal cell.
In prior art, the first liquid crystal aligning layer 15 and the second liquid crystal aligning layer 23 are produced on the color filter substrate and the array substrate by an inkjet process, respectively, and polyimide (briefly called as PI) is used for manufacture of the first liquid crystal aligning layer 15 and the second liquid crystal aligning layer 23. In the inkjet process, a polyimide liquid is firstly coated on a substrate by an inkjet manner, and a liquid crystal aligning layer with a uniform thickness can be obtained, as long as the polyimide liquid that has been coated on the substrate is subjected to free diffusion and heat curing for a certain time. However, in view of liquid surface tension of the polyimide liquid and limitation of liquid viscosity, there may be such a case that a non-uniform area is present at an edge of the finally obtained liquid crystal aligning layer. FIG. 2 is a partially enlarged view, in the peripheral area 5, of the first liquid crystal aligning layer 15 (or the second liquid crystal aligning layer 23) that is manufactured by using an existing technology. As shown by a dashed-line box in the figure, it can be seen clearly that an area, the thickness of which is non-uniform, is present at an edge of the liquid crystal aligning layer. The non-uniform area of the aligning layer will give rise to a disorder of the control on liquid crystals in the liquid crystal cell, so as to cause abnormality in display of the liquid crystal display device. In prior art, in order that this circumstance is escaped from occurring, and normal display of the effective display area 4 may be guaranteed, the following means is usually adopted: areas, the thickness of which is non-uniform, of the first liquid crystal aligning layer 15 and the second liquid crystal aligning layer 23 are made to exist outside the effective display area 4 in isolation. However, this means also results in the fact that a wider peripheral area is inevitably present in the liquid crystal display panel concurrently. For example, in the existing technology in FIG. 2, it is usually necessary that the distance between an outer edge of the liquid crystal aligning layer and the effective display area 4 reach 4.5 mm, leading to inability to minimize the design size for a portion of the display panel surrounding the effective display area.